In recent years, as one of measures against environmental issues, a hybrid vehicle that travels by driving force from an internal combustion engine and an electric motor for driving, and the like are receiving attention. In such a hybrid vehicle, abnormal noise, such as rattling noise of gears provided in a transmission including the electric motor for driving, may occur depending on the running condition of the vehicle.
In view of such a problem, Japanese Patent Laying-Open No. 2006-262585 (PTL 1) discloses a hybrid vehicle that prevents abnormal noise from occurring in a gear mechanism such as a change gear connected to an electric motor. This hybrid vehicle includes an internal combustion engine, electric power/motive power input/output means connected to an output shaft of the internal combustion engine and a drive shaft coupled to an axle shaft and capable of outputting at least a portion of motive power from the internal combustion engine to the drive shaft with electric power and motive power being input/output, an electric motor capable of inputting/outputting motive power to/from the axle shaft via the gear mechanism, power storage means exchanging electric power with the electric power/motive power input/output means and the electric motor, requested driving force setting means setting requested driving force requested of the axle shaft, target operating point setting means setting a target operating point of the internal combustion engine based on the requested driving force as set using predetermined restrictions, and control means that executes normal control when execution of normal control of controlling the internal combustion engine, the electric power/motive power input/output means and the electric motor such that the internal combustion engine is operated at the target operating point as set and such that the driving force based on the requested driving force as set is output to the axle shaft will cause the driving force output from the electric motor to fall outside a predetermined driving force range including zero, and executes abnormal control of controlling the internal combustion engine, the electric power/motive power input/output means and the electric motor such that the driving force output from the electric motor falls outside the predetermined driving force range and such that the driving force based on the requested driving force as set is output to the axle shaft, when execution of normal control will cause the driving force output from the electric motor to fall within the predetermined driving force range.
The hybrid vehicle disclosed in the above-identified publication can prevent abnormal noise from occurring in the gear mechanism that may occur based on the driving force output from the electric motor falling within the predetermined driving force range including zero.